libfaketime: make the build reproducible

A rebased version of https://github.com/NixOS/nixpkgs/pull/2281/commits/cb8bd05a0172db9c02ba0067b21bbc0ce17cc522
Note: we no longer apply the spurious lrt patch.

This allows `nix-build --check -A libfaketime` to succeed.

pkgs/development/libraries/libfaketime/default.nix

@@ -8,6 +8,10 @@ stdenv.mkDerivation rec {
     sha256 = "1dw2lqsv2iqwxg51mdn25b4fjj3v357s0mc6ahxawqp210krg29s";
   };
 
+  patches = [
+    ./no-date-in-gzip-man-page.patch
+  ];
+
   preBuild = ''
     makeFlagsArray+=(PREFIX="$out" LIBDIRNAME=/lib)
   '';